我正在创建一个小型计算器,它使用绑定创建多个值。有一个更好的方法吗?我觉得这完全是骇客。我是 Angular 的新手。
计算机:
<div ng-app="App" ng-controller="CalculatorCtrl">
<form action="javascript:;" id="calculator" class="form-inline">
<fieldset class="grid grid-4">
<div class="item">
<input required type="number"
ng-model="data.buy"
placeholder="Buy Price"
maxlength="10"
tabindex="1" />
</div>
<div class="item">
<input required type="number"
ng-model="data.sell"
placeholder="Sell Price/target"
maxlength="10"
tabindex="2" />
</div>
<div class="item">
<input required type="number"
ng-model="data.shares"
placeholder="Share Count"
maxlength="10"
tabindex="3" />
</div>
<div class="item">
<input required type="number"
ng-model="data.fee"
placeholder="Commission Fee"
maxlength="10"
tabindex="3" />
</div>
</fieldset>
</form>
<!-- Results -->
<table class="table table-bordered table-striped table-hover">
<tr>
<th width="150">Total Profit</th>
<td>{{ profit() | number:2 }}%</td>
</tr>
<tr>
<th width="150">Net Gain</th>
<td>{{ data.net = (data.soldFor - data.purchasedFor) | currency }}</td>
</tr>
<tr>
<th width="150">Purchased For</th>
<td>{{ data.purchasedFor = (data.buy * data.shares) + data.fee | currency }}</td>
</tr>
<tr>
<th width="150">Sold For</th>
<td>{{ data.soldFor = (data.sell * data.shares) - data.fee | currency }}</td>
</tr>
</table>
</div>
有问题的 JS(咖啡脚本):
# Core Coffee
app = angular.module 'App', []
app.controller 'CalculatorCtrl', ['$scope', ($scope) ->
$scope.profit = ->
data = $scope.data
return 0 unless data? and data.net? and data.purchasedFor? and data.soldFor?
a = if data.soldFor > data.purchasedFor then data.soldFor else data.purchasedFor
b = if a is data.soldFor then data.purchasedFor else data.soldFor
res = if data.net >= 1 then '+' else '-'
res += ((a - b) / b) * 100
]
如果没有这条线,我如何确保数据存在(就像 Angular 是如何自动执行的)?return 0 unless data? and data.net? and data.purchasedFor? and data.soldFor?
编辑:感谢Maxim,这非常有效:
### Watch for the net gain value and then calculate a profit % ###
$scope.$watch 'data.net', (newVal, oldVal) ->
return 0 unless newVal?
data = $scope.data
a = if data.soldFor > data.purchasedFor then data.soldFor else data.purchasedFor
b = if a is data.soldFor then data.purchasedFor else data.soldFor
$scope.data.profit = if newVal >= 1 then '+' else '-'
$scope.data.profit += ((a - b) / b) * 100